January 2, 2015
An estimated $10 million and more than 800 tonnes of toxic bait has gone into New Zealand’s biggest pest control project.
The Department of Conservation (DOC) said its Battle for Our Birds campaign had successfully knocked down predator numbers across key areas.
In January, Conservation Minister Dr Nick Smith announced the campaign in response to expected heavy seedfall from native beech trees, especially in the South Island.
The abundance of food was predicted to drive up mice and rat populations, which in turn would boost stoat numbers.
At the time, Smith estimated that the programme would cost about $21m over five years, out of DOC’s $335m annual budget.
Since August, DOC has treated about 550,000 hectares of conservation land with aerial 1080 across 25 operations. Two more operations – Makarora in Otago and the Poulter/Hurunui valleys in Canterbury – are scheduled for early 2015.
Project director Mike Slater said the “war was far from won” since rats and stoats would inevitably re-invade over time.
“But these operations will give some of our most vulnerable birds a precious window to raise their young this summer.”
In some operation areas rat numbers had dropped to almost undetectable levels after poison drops.
Slater said some native birds had been lost through the operations. Of 43 kea radio-tracked in Kahurangi and South Westland, three had died from 1080 poisoning.
Kea nest in natural cavities on the ground which makes them vulnerable to predation during breeding seasons. Slater said while it was unfortunate to lose any birds, “without protection most kea chicks are killed by stoats”.
“So the population gains from one good breeding season more than offset the losses of individual birds.”
In Kahurangi National Park, 25 rock wren were being monitored but DOC staff had been unable to locate the small alpine birds.
Slater said no dead rock wrens had been found so more work was required to find out what had happened.
“It’s not clear whether we have lost birds to heavy snow that fell in the area after the operation, 1080 or predator attack.”
The area treated with aerial 1080 in DOC’s Battle for our Birds alone was greater than all aerial 1080 use the previous year.
In December, the Environmental Protection Authority released its annual report on the aerial use of 1080. For the 2013 calendar year, aerial 1080 operations covered 448,210 hectares, the majority of which (298,397 ha) was treated by TBfree New Zealand.
– The Press